DNA used to stop MRSA outbreak

UK doctors have used DNA testing for the first time to halt an outbreak of MRSA.

Work to crack the bacterium’s genetic code led to them discover that one member of staff at the Rosie Hospital in Cambridge may have been an unwitting carrier and spread the infection.

Concerns were raised when routine screening showed MRSA had been detected in 12 babies at the hospital but existing tests were unable to determine whether it was a single outbreak, or separate cases.

Researchers at the University of Cambridge and the Sanger Institute turned detective to try to find out.

That involved using a sophisticated version of a paternity test and comparing the entire genetic code of MRSA from each baby to build a family tree, which revealed they were all part of the same outbreak.

Deep cleaning was carried out but two months later another case appeared, leading to tests on 154 staff members.

It revealed that one was carrying MRSA and could have spread it to the infants in the unit.

Dr Julian Parkhill from the Sanger Institute said while it may have brought the outbreak to a close, it also gave the hospital the opportunity to intervene and discover a new breakthrough in detection of MRSA.

“We think this is the first case where whole genome sequencing has actually led to a clinical intervention and brought the outbreak to a close,” he said.

The study was published in the medical journal Lancet Infectious Diseases and experts now believe it may soon become a standard approach in UK hospitals.